%0 Journal Article
%T More breast cancer genes?
%A John L Hopper
%J Breast Cancer Research
%D 2001
%I BioMed Central
%R 10.1186/bcr290
%X A study of Nordic families [1] has claimed 'preliminary evidence' that a region on chromosome 13q might contain a previously unrecognized tumour-suppressor gene, mutations in which may be associated with an unknown but probable high risk for breast cancer. This potentially exciting finding was achieved using new molecular techniques and 'a strategy that assumed that somatic genetic changes in cancer tissues may give insights to the nature of the germline predisposing loci'.Comparative genomic hybridization (CGH) was used to study tumours from multicase breast cancer families. Branching and phylogenetic tree models, and other evidence suggested that loss of 13q was an early genetic event in the development of breast cancers. All five tumours from one particular family showed distinct 13q deletions, which led to identification of a haplotype shared by all five affected members that coincided with the region of loss in the tumours identified by CGH. However, the 'significance' of the loss of homozygosity studies, in both the statistical and common language meanings, is difficult to assess, given that the role of chance was not evaluated.A linkage study, in an independent set of multicase breast cancer families in which BRAC1 and BRCA2 mutations had been excluded, was then targeted on the region of interest in their search for a novel breast cancer predisposition locus that they termed BRCAX [1]. They considered their lod score results promising, although there was no evidence of linkage in an interval that was only 0.5-2.1 cM from the position of their BRCAX. Those investigators were also confident that they could exclude the role of BRCA2, which is not far (recombination fraction 0.25) from where their putative locus lies, even though they did not study extensively markers on both sides of BRCA2. Is there really a BRCAX other than BRCA2 on this chromosome?Why would one think there are more genes associated with a high risk for breast cancer other than BRCA1 and BRCA2?
%K breast cancer
%K familial aggregation
%K genes
%K linkage
%K replication
%U http://breast-cancer-research.com/content/3/3/154